1 /* $NetBSD: db_access.c,v 1.21 2009/09/28 05:53:37 bsh Exp $ */ 2 3 /* 4 * Mach Operating System 5 * Copyright (c) 1991,1990 Carnegie Mellon University 6 * All Rights Reserved. 7 * 8 * Permission to use, copy, modify and distribute this software and its 9 * documentation is hereby granted, provided that both the copyright 10 * notice and this permission notice appear in all copies of the 11 * software, derivative works or modified versions, and any portions 12 * thereof, and that both notices appear in supporting documentation. 13 * 14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 17 * 18 * Carnegie Mellon requests users of this software to return to 19 * 20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 21 * School of Computer Science 22 * Carnegie Mellon University 23 * Pittsburgh PA 15213-3890 24 * 25 * any improvements or extensions that they make and grant Carnegie the 26 * rights to redistribute these changes. 27 * 28 * Author: David B. Golub, Carnegie Mellon University 29 * Date: 7/90 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: db_access.c,v 1.21 2009/09/28 05:53:37 bsh Exp $"); 34 35 #if defined(_KERNEL_OPT) 36 #include "opt_kgdb.h" 37 #endif 38 39 #include <sys/param.h> 40 #include <sys/proc.h> 41 #include <sys/endian.h> 42 43 #include <ddb/ddb.h> 44 45 /* 46 * Access unaligned data items on aligned (longword) 47 * boundaries. 48 * 49 * This file is shared by ddb, kgdb and crash(8). 50 */ 51 52 #if defined(DDB) || !defined(DDB) && !defined(KGDB) 53 #define _COMPILE_THIS 54 #endif 55 56 #if defined(_COMPILE_THIS) || defined(KGDB) && defined(SOFTWARE_SSTEP) 57 58 const int db_extend[] = { /* table for sign-extending */ 59 0, 60 0xFFFFFF80, 61 0xFFFF8000, 62 0xFF800000 63 }; 64 65 db_expr_t 66 db_get_value(db_addr_t addr, size_t size, bool is_signed) 67 { 68 char data[sizeof(db_expr_t)]; 69 db_expr_t value; 70 size_t i; 71 72 db_read_bytes(addr, size, data); 73 74 value = 0; 75 #if BYTE_ORDER == LITTLE_ENDIAN 76 for (i = size; i-- > 0;) 77 #else /* BYTE_ORDER == BIG_ENDIAN */ 78 for (i = 0; i < size; i++) 79 #endif /* BYTE_ORDER */ 80 value = (value << 8) + (data[i] & 0xFF); 81 82 if (size < 4 && is_signed && (value & db_extend[size]) != 0) 83 value |= db_extend[size]; 84 return (value); 85 } 86 87 void 88 db_put_value(db_addr_t addr, size_t size, db_expr_t value) 89 { 90 char data[sizeof(db_expr_t)]; 91 size_t i; 92 93 #if BYTE_ORDER == LITTLE_ENDIAN 94 for (i = 0; i < size; i++) 95 #else /* BYTE_ORDER == BIG_ENDIAN */ 96 for (i = size; i-- > 0;) 97 #endif /* BYTE_ORDER */ 98 { 99 data[i] = value & 0xFF; 100 value >>= 8; 101 } 102 103 db_write_bytes(addr, size, data); 104 } 105 106 #endif /* _COMPILE_THIS || KGDB && SOFTWARE_SSTEP */ 107 108 #ifdef _COMPILE_THIS 109 110 void * 111 db_read_ptr(const char *name) 112 { 113 db_expr_t val; 114 void *p; 115 116 if (!db_value_of_name(name, &val)) { 117 db_printf("db_read_ptr: cannot find `%s'\n", name); 118 db_error(NULL); 119 /* NOTREACHED */ 120 } 121 db_read_bytes((db_addr_t)val, sizeof(p), (char *)&p); 122 return p; 123 } 124 125 int 126 db_read_int(const char *name) 127 { 128 db_expr_t val; 129 int p; 130 131 if (!db_value_of_name(name, &val)) { 132 db_printf("db_read_int: cannot find `%s'\n", name); 133 db_error(NULL); 134 /* NOTREACHED */ 135 } 136 db_read_bytes((db_addr_t)val, sizeof(p), (char *)&p); 137 return p; 138 } 139 140 #endif /* _COMPILE_THIS */ 141